Charles prancis jenkins



c. F. JENHKINS will@ nunon original Filed oct. 31.. 1922v [Mmes FRAmsJeNKmg Jlis .lucent light Aaperture therein.

Reissued l1, 1927.

UNITED STATES PATENT OFFICE.

CHARLES FRANCIS JENXINS, 0F WASHINGTON, DISTRICT 0F COLUMBIA, ASSIGNOB T0 y JENKINS LABORATORIES, .A CORPORATION.

FLE'XING MIRROR.

original No. 1,525,550, dated Fem-naw 10, 1925, seria11w.5es,145, ined october 31, 1922. Application i'nr reissue' led January 10,

This invention relates to apparatus for receiving pictures-by-radio, and has for its principal object means for`varying, with a fluctuating current, the intensity of the light falling on a given area.-

In the ligure, A is a light source; B a lens for gathering the diverging rays of the light source and direct-ing them onto mirror C, from which the light is .reflected to an apertured disc D, with a transparenter transl`he glass mlrror C, which may b e a strip, a disc, or

shape most suitable for the purpose,l is

jacent to the pole piece of an electric magnet having leads F.

The beam of light directed on the mirror, and from there reected to the mask D has its boundary shown by solid lines in the drawing. This is the boundary when the diaphragm is in inactive or neutral position.

- When the iron diaphragm is pulled down by current in the leads F, the boundary of the vbeam of light between the mirror E and the mask D will be more concentrated, as shown by the dotted lines, because the mirror is concave. However, When the diaphragm is repelled over the pole of the magnet by current of opposite sign in the leads F, the mirror will be made convex, andthe beam reflected therefrom will be wider, as shown bounded -b the dash lines. The effect then of a pu sating or alternating current in the 'leads F is to cause the cross sec tion of the beam of light, where it falls on the mask, to have greater or lesser area.' As the area is lessened the intensity over unit area is obviously increased, and if the area considered is that in the middle of the mask D, it is just as obvious that this area will fluctuate in strength of illumination in y accord with the amplitude of vibration of the mirror.

This then is the object sought, namely, means for increasing or decreasing the intensity'of t-he illumination of a given area to corrspond vto the fluctuation in the cur` rent strength of the leads F.

The fluctuating current in the leads F follows the light values of in a receiving station, of which this device is a art.' The changing intensity of the spot on tEe mask D is imaged on a photographic` pictures being sent vfrom a broadcasting statlon and picked up 1927. Serial N o. `1130,318.

plate P in this tures-by-radio, andA is distributedover-the plate in proper order to reproduce the original picture by any suitable and Well known device.

vWhat I claim 'isz l. In apparatus of tlie class described, a light source, a flexible mirror located to rellect light from said source, an electro-magnet and its armature, attached to the mirror, with the axis of the reflected light, and an apertured' mask between the lens and light source, the area of the a erture being but a. fraction of .thearea of t e adjacent surface of Said lens.

2. In combination, a source of light, a light receiving surface, means for directlng` a beam of light from said source towards ,said surface,' an apertured mask located beltween said source and said surface to'nor- 75 mally permit only a portion of said beam to reach the surface, a lens arrangedv in alignment with the axis of the reiiected light and located between the apertured mask and the light receiving surface and being of ma- B0 terially a greater area than the aperturedy mask, andmeans to alternately concentrate' and disperse said beam to thereby vary the amount of light transmitted through said means,

3'. In combinatioma source of light, a

light receiving surface, means associated andlocated between the light screen and the 96 light receiving surface and having an area materially'greater than the aperture in the light screen, .and means to` alternately concentrate and dispersesaidbeam to therebyV vary the amount of light transmitted 100 through said aperture.

4. The combi-nation of a source 4of light of constant intensity, a light receiving'surface, means associated with said source for directing a beam of light along a iixed axis *105 towards said light receiving surface,a light screen located in the path of said beam,

said screen being provided with an aperprocess of transmitting pic- 5i the 'armature being I a lens in alignment 66.

a light screen located in 90 the axis of face, meanebassociated arranged in alignment with '.t-he axi's'of the ,retlected light vand located between the light towards the light 'receiving light variations ofa picture being trans- 'of constant intensity, face, means including `a f ing a `wards said light receiving ture normally smaller light, a lensv arranged the reflected 'light andlocated between the light screen and the lightreceiving surface and having an area .ma- Aterially greater. than" the aperture of the than the beam of screen, and means to vary the concentration or" said beamin accordance with light variations oi successive picture areas. 5. The combination of a source of light of constant intensity,y a light receiving surwith said source for eam'of light along a fixed vaxisv surface,v a light screen located inthe path of the beam, said directing a screen being'provided'with van aperture normally smaller than the beam of light, a lens screen and the light receiving surface and having an area materially greater than'the aperture of `the screen, a source of current varying in amplitude in accordancewith mitted, Aand means controlled by said source of current for varying 'the concentration of said beam n accordance with amplitude va- Y a Lsources-of lightl a light receiving s'ur-.

riationsy of said current.

6. The combination of beam of lightjalong a xedaxis to? surface, a light screen located in the `'path of said beamfsaid 1n alignmenti with `reiected light and mirror for "direct-i screen being provided with an' apertureinor'- 35 mally smaller than the beamof light, a lens arranged in alignment with the axis of located between the light screen and the light receivingsurface and having an area materially greater than the aperture of thescieen, -a source of current varying in amplitude fin accordance with light variations cf a'picture being trans- 1nitted,;andmeans Lcontrolled by saidsource 45 the concentration of said beam in accordl ance 'with amplitude variations of said cur-v of current. for lexing said mirror to vary rent.

7. The of constant intensity,

a light receivin'grsurface, meansasscciated with said source for directing a beam lof iight along a; fixed axis'.

receiving surface," a light towards said light screen' located inthe path of the beam, said vscreen being provided-with an aperture normally lsmaller thauthe beam of light, `a'lens `arranged in alignment with the axis 'of the vreflected light and located between the light` screen and thev light receiving surface' `and v a source ,otcurrent- -.varying in amplitude, and .means controlled .source of .current for varying the .cQncentration-c `saidbeamwith amplitudevariation's of said current. 05

havingan area `materially greaterthan-the aperture othe screen,

by saidin accordance CHARLES 'runners Jnruinas,

thel v vcombination of a source of light-A.`

ereofI axmy signature.A 

